At least when Democrats lost their minds for Jon Ossoff in 2017, the quixotic electoral effort in Georgia had the virtue of novelty. In 2018, their massive bet on Robert "Beto" O'Rourke in Texas might cost them any chance to take control of the Senate.

Ossoff was the Young Handsome Democrat Du Jour in 2017, running in a special election to fill the vacant seat of Tom Price, whose short-lived stint as Health and Human Services secretary hardly made it worth the bother. Democrats poured tens of millions of dollars into the special election for a House seat that they likely wouldn't be able to hold in the next election; the Cook index rating for Georgia's 6th Congressional District has a six-point advantage for Republicans. The big push for Ossoff was intended to show that Democrats could compete in the GOP's traditional districts, post-President Trump.

The race ate up over $50 million in donations, with Ossoff handily outraising Republican nominee Karen Handel. In the quarter prior to the special election, Ossoff brought in and spent $20 million from all around the country. And in the end, Handel won 52 percent to 48 percent. That was much closer than Price's margin the year before (62-38), but still a loss. On the same day, Roll Call's Patricia Murphy recalls, Democrat Archie Parnell lost a special election in South Carolina's 5th Congressional District (Cook index: R+9) to Republican Ralph Norman 51-48, with only a small fraction of the resources directed to Ossoff. "A staffer there told me that even $100,000 of Ossoff's $30 million could have won the race for them," Murphy wrote this week. "Instead, they both lost."

That should have taught Democrats a lesson. But they didn't learn it. This time around, their Young Handsome Democrat Du Jour may cost them their chance at the Senate.

Ironically, it's the good news for O'Rourke this week that makes this plain. Thanks to a highly organized national effort, O'Rourke's campaign raised $38 million in the most recent quarter, from July through September. That almost tripled incumbent GOP Sen. Ted Cruz's $12 million in the same period. O'Rourke has led in all three quarters this year by a 2:1 margin or greater, even when accounting for the outside PAC money raised for Cruz. On fundraising prowess alone, O'Rourke has turned in the best performance since … Jon Ossoff.

What did all that fundraising buy? Almost no movement in the polls. Cruz leads across a variety of pollsters this week by an even greater margin than last month. A new CNN poll puts O'Rourke behind by seven, a New York Times/Siena poll has him down eight, and Quinnipiac has the gap at nine points. All three plus a CBS/YouGov poll have Cruz at 50 percent or above, safe ground for an incumbent with less than three weeks to go. O'Rourke's average polling support has barely budged despite that massive infusion of cash from all over the country, going from 42 percent at the beginning of summer to just under 44 percent now.

Just as with Ossoff, the ridiculous amounts of money invested in a long-shot bid in deep red territory didn't change the dynamics of the electorate involved. However, it ate up resources that could have been used for other gains. The big bet on O'Rourke might end up costing Democrats Nevada, and maybe more.

Incumbent GOP Sen. Dean Heller has been considered one of the most vulnerable senators running in this cycle. Nevada went narrowly (48-46) to Hillary Clinton in 2016, making Heller the only blue-state Republican senator in the midterm mix. Even so, Heller has kept close to Democratic challenger Jackie Rosen, only trailing outside the margin of error in one June poll but generally remaining slightly back. Over the last week, however, two polls (NBC/Marist and NYT/Siena) put him slightly in the lead for the first time since mid-summer, two points up on Rosen. This week, an Emerson poll showed Heller up to the largest lead for either candidate in the entire cycle — seven points, 48-41.

Haven't heard much about Jackie Rosen? The first-term congresswoman didn't get much attention from the national media, nor did she benefit from the kind of "Kennedyesque" mythologizing that O'Rourke received from his party. Rosen has done a decent job of raising money, tripling up Heller in the third quarter, $7.1 million to $2.2 million, but she burned through it, too. They started October with nearly identical cash-on-hand figures, even while her polling status eroded. Even a tenth of O'Rourke's haul might have made a big difference in a race Democrats thought they had in the bank.

And let's not forget New Jersey, where scandal-tarred Democratic incumbent Robert Menendez should be sailing to a win over political novice Bob Hugin. Two weeks ago, I noted that Menendez' polling had slipped to a dangerous single-digit lead in the overwhelmingly blue Garden State and warned that Democrats might have to shift resources from other races to rescue him. Sure enough, Chuck Schumer's Senate Majority PAC has just set aside $3 million to boost Menendez in the final days of the campaign. The money will go to last-minute TV ads tying Hugin to Trump in a state Hillary Clinton won by 14 points just two years ago.

O'Rourke's money might have come in handy in New Jersey. That money, and the Senate Majority PAC cash, won't help in Nevada, which was the Democrats' best opportunity for a pickup. It won't go to Tennessee or Arizona to compete for open seats left by Republican retirements. Nor will any of it go to Missouri, North Dakota, Florida, Montana, or Indiana — red states with endangered Democratic incumbents.

There is a cost to mythologizing candidates in long-shot races. Democrats may pay dearly for it in November.